Compbession spray gun



I. W. P. BUCHANAN M 2, 1933, comrnrzssloiq SPRAY cu R 18,813

2 Sheets-Sheet 1 Original Filed April 12, 1929 I. 2. .Rfiuchanaw 2INVENTOR BY w am ATTORNEY l. W. P. BUCHANAN 2 Sheets-Sheet 2 OriginalFiled April 12, 1929 f. E7. ffl iuchanan/ INVENTOR ATTORNEY ReissueclMay 2, 1933 UNITED STATES ISAAC W. P. BUCHANAN, OF- LEBANON", TENNESSEE-oomranssiou SPRAY- GUN Original No. 1,744,208, dated January 21, 1930,Serial at. 354,668, fii'eda rn 12, 1929'." Application for reissue filedSeptember 22, 1931.

This invention relates to a compression spray device or gun, the presentinventlo'n being an improvement over that'forming' the subject matter ofan application filed by'me on'February 15, 1928, Serial No. 254,510, the

general object of the invention being to provide means whereby-theliquid is ejected by pressure as well as suction so that the'device;

will operate with the minimum amount of compressed air, this air beingused to create pressure 111 the container above the liquid therein andalso used to create suction in the and which last are only capable ofinferior functioning. Also in addition to this firsttime-accomplishedportability, only a P. motor is required, which can be attached,

without danger, to any electric lightlamp socket.

i A further object of the invention is to provide atip' having a slottherein {or producing a fan-shaped spray andto so'form the-tip and its'slott-hat the central portion of the fan-shaped spray will be thickerthan the'end portions or edges of the spray, so that the swaths of paintor thelike, sprayed on a surface by the device, can be made to overlapwithout'the laps being thicker than the other portions'and withoutcausing runs;-

As will beseen, the interior walls of the 40 tip'terminate in the slit,and so converge as to produce a fan shaped spray of fixed flare limits.I

The object of my slitt-edtip is to produce a fan shaped spray andWhichso co-acts with theadjustable liquid control valve as to producefan shaped sprays varying in width between one-half inch and sixteeninches,- or

more;

A'further object of 'the'invention is to-pro- W videan adjustable mixingchamber, with Set- Serial no. 564,703.

bilizing means for producing a homogeneous cross section of a fan-shapedspray, this-mixing 'ch'amber ermitting the air and liquid to intermingleunder pressure before escaping fromthe tip, thus producing a fan-shapedspray of uniform cross section and allowing the fan shaped spray to bearranged-either vertically or horizontally.

Afurther object of the invention is to provide adjustable means forrestricting the flow of air after-it has contacted-the-li'quid. Itsfunction is to increase the volume of liquid tobe atomized. This meansis especiallydesirable in connection with large stationary corttainersin which last case the needle valve 6, Figure 2, can be used.

Anotherob'ject of the invention is to provide a disk carrying a valve,the disk being located between the container and the atomizationhead-andacts to :prevent the liquid in the container from entering the head,while permitting air to enter the container from the head to place thecontents-thereof under-pressure." This disk, of course-, cou'ld beintegr'akwith' atomizingh'ead.

Another object of the invention is topro-' vide apressure controlvalvefor closing the air supply'lineto the container so that thecontainer can be removed and filled without stopping the power plantthat supplies compressed air to the device.

A still further object of the invention'is to provideadjustingscrewsintheeduction tube to?) centering the liquid tube in the-*eductiori tu e.-5

Another object .of the invention-is to. provide a manually operatedvalveinterruptingthe-flow ofliquid through the liquid tube withoutinterfering with the airflow, so that the spraying can be stoppedinstantly and then when the valve'is opened to permit the liquidto flowagain, the same t'extureof atomization is producedas was produced'beforethe valve was closed, with simple means foradj'usting said valve so asto control the fineness and volume of spray.

The adjustable liquid valve for starting and stopping the flow ofliquid, also gauges the amount of-liquid delivered at each trig geroperation.

This adjustment allows this valve to co-act with the slitted tip so asto produce fanshaped sprays varying in width from onehalf inch tosixteen inches or more.

Large quantities of liquid entirely fill out the fixed air contour ofthe fan-shaped spray, and smaller quantities of liquid fill the center,only, of this fixed air contour.

This invention also consists in certain other features of constructionand in the combination and arrangementof the several parts, to behereinafter fully described, illustrated in the accompanying drawingsand specifically pointed out in the appended claims.

In describing the invention in detail, reference will be had to theaccompanying drawings wherein like characters denote like orcorresponding partsthroughout the several views, and in which Figure 1is an elevation of the invention.

Figure 2 is a top plan view. I

Figure 3 is a vertical sectional view, with parts in elevation.

Figure 4 is a section on line 4'-4 of Figure 2.

Figure 5 is a section on line 55 of Figure 2.

Figures 6 and 7 are views of the valve carrying disk.

.Figure 8 is a longitudinal sectional View through said disk.

Figures 9, 10, 11, 12 and 13' are views of the tip. r In these drawings,the numeral 1 indicates a container, the neck of which is threaded toreceive a cap 2, the cap being provided with a hollow dome 3 into whichair is introduced from a suitable source of supply through a tubeconnected with the inlet mem her 4, which in turn is connected with avalve casing 5, one end of which is threaded in a hole in the dome.Thismember carries the needle valve 6, the closing of which prevents airfrom entering the dome. The. valvecasing 5 also carries a safety valve 7for preventing damage to the pressure;

A depending tubular part 8 is formed at thecenter of the dome and asection 9 of a liquid tube is threaded into the depending} portion, thelower end of the section extending to a point adjacent the lower end ofthe container. The other section lOof the liqquid tube is threaded intoa horizontal opening formed in the upper end of the depending part sothat liquid can pass from the section 9 through the tubular part8 intothe section 10, it being seen that the section 10 extends horizontallyand at right, angles to the section 9. An eduction tube 11 surroundsthesection 10 of the liquid tube and has one end threaded into an opening12 formed in one side of the dome and an air tube 13 connects the innerend of the opening 12 with the lower part of the chamber 14 formed byparts by excessive the hollow dome so that air can pass from the chamber14 through the tube 13 into the eduction tube. As will be seen, thesection 10 of the liquid tube passes through the opening 12 and is notin communication there with. I

The air tube 13 is provided with an opening 15 which is controlled by aset screw valve 16 threaded through a packing gland 16 in the dome, sothat by adjusting the set screw valve, the escape of air into theeduction tube can be regulated. This arrangement permits the air passingto the eduction tube to be regulated from the exterior of the dome andwhile the device is in operation.

Itwill, of course, be understood that aft-er the valve 16 is adjusted,the same amount of air will always be passing to the eduction tube,since;the compressor is delivering the same amount of compressed air tothe dome, and all of this air will pass through the tube 13 to theeduction tube. By adjusting the valve 16, the passage of the air to theeduction tube is more or less restricted, and therefore causes more orless pressure on the liq-v uid in the container. It is also observablein Figure 3 that by adjusting the tip 27, very near the end of-theliquid tube 10, the same kind of air-passage restriction would result.

The flow of liquid into the section 10 of the liquid tube is controlledby a needle valve 17 passing through a packing gland 18 in thehead,'with its pointed end engaging a seat 20 against. which the innerend of the section '10 abuts. The outer end of the needle valve isthreaded in the head 21 of a tubular stem 22 which is slidably arrangedin the upper part of the handle 23 of the device, this handle having ahorizontal part 24 at its upper end which is bolted or otherwise securedto the top of the dome. A knurled member 19 is fastened to the stem ofthe needle valve to facilitate turning of the same; A coil spring 25 isarrangedon the stem 22 and bears against a part of the handle andhead 21and acts to hold the needle valve onits seat 20. A trigger 26 has itsupper forked end. pivoted to the part 24 of the handle, a portionof thetrigger engaging the head 21 so thatjwhen the trigger is movedrearwardly by one or more of the fingers of the hand grasping the handle23, the needle valve will be moved to open position,

A tip 27 is threaded on the outer end of the eduction tube so that itcan be adjusted toward and away from the end of the section 10 of theliquid tube which protrudes from the eduction tube. This tip is formedwith a slot 28 and with a conical interior part 29 and at the pointwhere the; slot enters the chamber formed by the conical part, asubstantially elliptical opening is formed for the escape of the mixtureof air and liquid so that a fan-shaped spray is produced, the center ofwhich is of greater thickness than the ends or edges. The chamber formedby the conical part 29 provides a mixing chamber wherein the liquidpassing from the section 10 oftheliquid'tube and the air 5 passing fromthe eduction tube can intermingle beforethe mixture escapes from thesplitin the'tip. The tip is locked inadj usted position by the nut 30whichis thread ed on the eduction tube and the gasket 31 which is placedbetween the-"nut and the rear end of the tip. By making the tipornoz'zle adjustable, the slot thereincan be placed in either ahorizontal or vertical position, so that'th'e spray will pass trom'thenozzle in either a'hori'zontal or vertical position.

While the drawings show the section 10 of the liquid tube passingentirely through the eduction tube. I find that this section 10 can begreatly shortened or even omitted without interfering withtheoperation'of the device.

A disk 32 is placed between the neck of the container and the cap,gaskets 33'being placed between the disk and the cap and between thedisk and the neck of the container to make a liquid andairtight'junction at this point, said disk being formed with an opening34 therein which is closed by a flap valve 35 opening downwardly'so thatair can en'- ter the container from the dome, but liquid cannot passfrom the container into the'dome. A handle 36 is connected with'th'edisk to facilitate its removal. liquid tube passes snugly through a=hole37 formed in the center of the disk.

A threaded projection 38 is formed on thetop of the part 24 of thehandle and is designed to receive an extra tip 39 which may besubstituted for the tip 27, the tips being of different sizes. Ofcourse, more than one projection 38 can beplaced on the part 24 toreceive other tips.

From the foregoing it willbe' seen that; when the inlet member 14 isconnected by a hose to a source of'compressed air and the valve 6opened, the air will enter the chamber 14formed by the hollow dome andsome of this air will pass through the valve covered opening in the disk32 into the conta iner and thus place the contents of the containerunder pressure. This will'tend to force the liquid in the containerthrough the section 9 of the liquid tube, but the liquid is preventedfrom passing into'the section 10 by theneedle valve 17. Some of the airin the chamber 14 will pass through the tube 13 into the eduction tubeso that when the trigger 26 is operated to open the valve 17 the liquidwill flow through the sections of the liquid tube into the mixingchamber in the nozzle or tip, where it will'be' mixed The section 9 ofthe suction. The mixture of air and liquid pass ing through the slot 28will take the-form ofia fan-shaped spray and due to the=iellipticalshapeof the opening, the 'spray will be of greater thickness at thecenter'than at its ends or edges, so'that the swath of paint orothermaterial being sprayed on a surface can-be overlapped withoutunduly-thickening the overlapping portions and without producing runs atsaid-portions.

If the swath: is not uniform, thetip should beadjuste'd until the'tswathis uniform This tip, with the adjustable mixing chamber formedby thetip; and the outerend of the eduction tube, will produce fan-shapedsprays'up to twenty-inches in width at'th'eordinary distance ofapplication, and attentionjis called to thefact that while theadjustablemixing chamber is apparentlylike the sprayer, since'the hol in 'the tipis very small, the air cann'ot escape asrapidly' as it is suppliedandthe consequence is that there is a greater or smaller pressure"exerted on the liquid emergingfrom the liquid tube,'an'd this liquid istherefore allowed to mix with smaller or larger quantities 0am,- thusproducin'g variable atomizations. Themixing chamber in this application,however, does not allow'air' to backup and decrease the emergingliquid,- as thelong'slit in thetip permits the air to'escape.

Aswill be understood, when a largel'qu an' tity of liquid is forcedthrough the nozzle or" tip ,the'swath will be of the maximum width, butwhen the quantity of liquid is decreased by the adjustment of the'needlevalve, the

width of the swath is reduced as the liquidpasses from the central partof theslit and nothing but air passes from the ends-'ofthe" slit; as theair envelopes the reduced quantity of li'quid and thus this-reducedquantity of spraying through the air tube13 when thegun tilted more thanusual.

The pressure control valve6 can be closed Without stopping thepowerplant so that'- the container can be refilled or changed.

The section 10 of the liquid' tub'e iscenter'ed. in the eduction tube'bythree'small screws-4O and byadju stin gthe needle valve 17::in'theheadfilgthe'amount ofliquid passing through the liquidtu'be-can becontrolled 'or regulated" when the valve is open.

This device, while adapted to agricultural and horticultural needs, ismainlyintended for the spray application of paints and lacquers and canbe used with a minimum amount of compressed air and as it is of smallweight, it'can be-easily carried from place to place.- As but a smallpower plant is necessary to furnish the air, the motor of the plant canbe used with the ordinary'house current. The texture of atomization isfrom the faintest tint to any desired degree of coarseness.-

Therefore, we have a portable and an electric lamp socket-attachableplant'doing much faster work than competing plants that are neitherportable nor' capable of being attached, for their power, tov ordinaryelectric light sockets. f a

The slit in the tip may be formed by a straight slot, as shown inFigures 9, 10 and 11, though it is. preferable to form it by a V- shapedslot, as shown in Figures 12 and 13.

a It is thought from the foregoing description that the advantages andnovel features of the invention will be readily apparent.

It is to be understood thatchanges'may be made in the construction andin'the combination and arrangement of therseveral parts, provided thatsuch changes fallwithinthe scope of the appended claims.

What I claim is V 1. A compression spray gun for use with a supply ofair under pressure, comprising a liquid container, means for introducingcom pressed air into'the container to place liquid therein underpressure, an induction tube associated with the container and throughwhich some of the compressed air passes, ad

justable means for restricting the escape of air from thecontainer intothe induction tube after it contacts the liquid, a nozzle mounted on theeduction tube a liquid tube connecting the interior of the containerwith the space enclosed by the nozzle and eduction tube,

and valve means associated with the liquid tube for starting, stopping,and operatively controlling the flow of liquid therethroughwithoutinterrupting the flow of air through the eduction tube. r

.2. A power spray gun comprising a hollow head, acontainer detachablyconnected therewith, means for introducing compressed air into the head,an eduction tube connected with the head and in communication'withtheinterior thereof, a nozzle having an elongated slit thereinassociated with the outer end of the eduction tube, a liquid tubecarried by the head and connecting the interior of the container withthe space enclosed by the nozzle andeduction tube, adjustable means forrestricting the escape of air from the container into the induction tubeafterit contacts liquid, a hand operated valvefor controlling the flowof liquid through the liquid tube, a needle valve passing through thehead tube,means for adjusting the valve.

3. A power spray gun comprising a hollow head, a container detachablyconnected therewith, means-for introducing compressed air into the head,an eduction tube connected with the head and in communication with theinterior thereof a nozzle having an elongatedslit therein adjustablyconnected'with theouter end of theeduction tube, a liquid tube carriedby the head and connecting the interior of the container with the spaceenclosed by the nozzle and eduction tube, ad-

justable means for restricting the escape of air from the container intothe eduction tube after it contacts liquid, a hand operated valve thehead, means for introducing compressed air into the head, someof thisair entering the container for placing liquid therein under pressure, aneduction tube connected with the head and in communication therewith, anadjustable nozzle on the outer end of the eduction tube having anelongated slit therein forming a fan-shaped spray, adjustable means forrestricting the escape of air from the container into the eduction tubeafter contacting the liquid in said container, at liquid tube carried'bythe head and connecting the interior of the container with the spaceenclosed by the nozzle and eduction tube, a needle'valve stem passingthrough the head and when in closed position preventing thefiow ofliquid through the liquid tube, means for adjustably connecting theneedle valve stem to a trigger pivoted to the handle, whereby the valve'will be unseated when the trigger member is operated, and withoutinterrupting the flow of air through the eduction tube.

5. A power spray gun comprising a hollow head, a container detachablyconnected therewith, an angle-shaped handle connected,

necting the interior of the container with the space enclosed by thenozzle and eduction and when in closed position preventing the flow ofliquid through the liquid tube, a spring pressed slidable memberassociated with the handle, means for adjustably connecting the needlevalve to said member, a trigger pivoted to the handle and engaging apart of the slidable member whereby the valve will be unseated when thetrigger member is moved toward the handle, a Valve carried by the headfor closing communication between the head and the air supply, a safetyvalve associated with the head, and means for centering the liquid tubein the eduction tube.

6. A spraying device comprising a container, a cap therefor, a hollowhead mounted on the cap and having a space in communication with thecontainer, an eduction tube mounted in the head and in communicationwith the interior of the head, a liquid tube means carried by the headand having a part extending into the container and another partextending into the eduction tube, a source of compressed air feedinginto the hollow head, a partition separating the air space of the hollowhead from the container 'and having an opening therein, means forcontrolling the openin whereby air can pass from the head into thecontainer to force liquid therein to the eduction tube and wherebyliquid is prevented from passing from the container into the head, andmeans for causing air passing through the eduction tube to act on theliquid emerging from the liquid tube, comprising a nozzle on the foreend of the eduction tube.

7. A spraying device comprising a container, a cap therefor, a hollowhead mounted on the cap and having a space in communication with thecontainer, an eduction tube mounted in the head and in communicationwith the interior of the head, a liquid tube means carried by the headand having a part extending into the container and another partextending into the eduction tube, a source of compressed air feedinginto the hollow head, a partition separating the air space of the hollowhead from the container and having an opening therein, means forcontrolling the opening whereby air can pass from the head into thecontainer to force liquid therein to the eduction tube and Wherebyliquid is prevented from passing from the container into the head, andmeans for causing the air passing through the eduction tube to act onthe liquid emerging from the liquid tube, comprising a nozzle on thefore end of the eduction tube, said nozzle having an elongated slittherein to produce a fan-shaped spray.

8. A compression power gun for producing a fan-shaped spray, comprisinga liquid container, a means for introducing compressed air into thecontainer, an eduction tube associated with the container and throughwhich the compressed air passes, a slitted nozzle mounted on theeduction tube, having its interior walls terminating in the slit and soconverging as to limit the flare of the fanshaped spray, a liquid tubeconnecting the interior of the eduction tube with the container, a valvefor controlling the flow of liquid through the liquid tube, whereby theflow of liquid is started and stopped, and means for adjusting the valveto regulate the quantity of liquid passing through the nozzle, wherebythe valve co-acts with the nozzle for producing fan-shaped sprays ofvarying widths.

9, A compression power gun for producing a fan-shaped spray, comprisinga liquid container, a means for introducing compressed air into thecontainer, an eduction tube associated with the container and throughwhich the compressed air passes, a nozzle having an elongated slittherein, and associated with the outer end of the eduction tube, aliquidtube means having a part extending into the con tainer and another partextending into the eduction tube, a valve for controlling the flow ofliquid through the liquid tube without interrupting the flow of airthrough the eduction tube, whereby the flow of liquid is started andstopped, and means for adjusting the valve to regulate the quantity ofliquid passing through the nozzle, whereby the valve co-acts with thenozzle for producing fanshaped sprays of varying widths.

ISAAC W. P. BUCHANAN.

